Fluorescent sensor array based on emission enhanced gold nanoclusters for detecting and discriminating pesticides in vegetables.

Fluorescence metal nanocluster (FMNC) sensor arrays have demonstrated high potential in simultaneously detecting multiple pesticides. However, the available FMNC arrays commonly depend on single interactions, which limits their application potential. In this study, a four-channel fluorescence sensor array consisting of enhanced Au-ATT/Tb, Au-ATT/CB[7], Au-ATT/Sc, and Au-ATT/Arg NCs was constructed based on multiple interactions of cucurbit[7]uril (CB[7]), Sc3+, Tb3+, and arginine (Arg) with gold-6-aza-2-thiothymine NCs (Au-ATT NCs). The sensor array simultaneously and distinctly discriminated four pesticides through various interactions, including charge transfer, hydrophobic, and metal complexation. Based on the differential fluorescence quenching degrees, the pesticides were quantitatively and qualitatively detected with detection limits of 0.174, 0.140, 0.120, and 0.819 μM for diquat, thiram, paraquat, and thiophanate-methyl, respectively. The array demonstrated excellent selectivity, high discrimination ability for pesticide mixtures, and 100 % identification accuracy in carrot, cucumber, and lake water samples at low concentrations, signifying the potential practical application of the proposed method.